Anthropologist Says Need to Pacify Babies Led to Birth of Language

Newswise — Every mother does it.

Talks to her baby in "baby talk," that is, and the reason dates to our earliest human ancestors as they first began to walk upright, according to a new theory proposed by an internationally known Florida State University anthropologist.

In a paper published in Behavioral and Brain Sciences, Professor Dean Falk says the universal language of "motherese," which is characterized by a high pitched voice, long drawn out vowels, repetitive phrases and a sing-song cadence, may hold the key to the emergence of language in humans and still plays an important role in how babies learn to talk.

If language is tied to two other hallmarks of evolution - upright walking and bigger brains, as Falk suggests - that means that full blown language began about 1.6 million years ago. That's eons earlier than 100,000 years ago when other anthropologists say language began.

"The epiphany for me was that I knew chimp mommies don't make these noises, so I knew something happened during evolution," she said. "The missing puzzle piece was bipedalism. We stood up; we lost hair. It was then that babies could no longer hang on to their mothers. Mothers had to hang on to their babies.

That was a eureka moment."

Falk theorizes that the evolutionary development of bigger brains meant that early humans began giving birth before their babies' heads became too big to pass through the birth canal. This shorter gestational period meant that humans - then and now - give birth to babies that are relatively undeveloped physically compared to other primates.

While chimpanzee infants can cling to their quadrapedal mothers and ride along on their bellies or backs, helpless human babies had to be carried everywhere - a situation that forced these early two-legged mothers to put their babies down next to them while they foraged for food. To ease their babies' distress over this separation, Falk believes mothers began to use vocal reassurances - thus the beginnings of baby talk.

The mothers who used vocalizations most effectively had higher survival rates both because they could gather more food and they were able to keep their children from making sounds that would attract predators, according to Falk. As mothers increasingly relied on vocalizations to control their babies and later their young children, words developed and became conventionalized across hominid communities, ultimately blossoming into language.

"The behavior of chimp mommies and babies and human mothers and infants are delightfully identical in many ways - the gestures and the facial expressions - but we are dramatically different in other ways," she said. "We vocalize continually in a way that helps babies begin to learn language by the end of the first year. I wanted to find out why we are the only animals that talk, and this need to pacify our babies as humans evolved may be the reason."